Strukton Afzinktechnieken – trade name MERGOR – has immersed the 9th tunnel element of Total 18 pieces between Jungjuk and Gaduk Island at the South Korean city of Busan.

With this milestone 50% of the elements for the Busan-Geoje Fixed Link Project are immersed within 13 months time as scheduled. The Busan-Geoje Fixed Link Project consists of a 3,2 kilometre long immersed tunnel and 2 cable-stayed bridges. After completion the required time to travel between Busan and Geoje will be reduced from 2,5 hours to just 50 minutes.

Tugboats have transported the element 2 days ago over a distance of 35 kilometres from the temporary mooring site at the construction location to the immersion location. Next the specialists of Strukton Afzinktechnieken have successfully immersed the element with a weight of 48000 ton at a depth of 37m on the seabed.

The required diving work and checks during the complete immersion operation were done bij Strukton company OTN, for which the de Self Propelled Diving Bell (SPDB) ‘Aurora’ is deployed. The SPDB is a state of art fitted and completely revised submarine with all required navigational equipment on board and can be utilised to depths up to 300m! The SPDB is not only deployed for inspections but for under water activities as well. Together with the pilot and co-pilot divers can travel in the SPDB and use it as a diving bell or interlock the SPDB to the immersed tunnel element and access the tunnel. The use of the SPDB for an immersion project is a first, not only for Strukton Afzinktechnieken but for the complete branch as well.

The immersion of the remaining 180 meter long elements will be done with 2 large catamaran pontoons which are equipped with a unique anchoring and positioning system.

Next step in the project for Strukton Afzinktechnieken is to immerse the deepest elements in open sea at a depth of 55 meter.